1. Technical Field
The present disclosure relates to acoustic devices, particularly, to a thermoacoustic device.
2. Discussion of Related Art
Acoustic devices generally include a signal element and a sound wave generator. The signal element inputs signals to the sound wave generator such as a loudspeaker. Loudspeaker is an electro-acoustic transducer that converts electrical signals into sound.
Thermoacoustic effect is a conversion between heat and acoustic signals. When signals are inputted into a thermoacoustic element, heating is produced in the thermoacoustic element according to the variations of the signal and/or signal strength. Heat is propagated into surrounding medium. The heating of the medium causes thermal expansion and produces pressure waves in the surrounding medium, resulting in sound wave generation. Such an acoustic effect induced by temperature waves is commonly called “the thermoacoustic effect”.
A loudspeaker based on the thermoacoustic effect was created by Fan et al. (“Flexible, Stretchable, Transparent Carbon Nanotube Thin Film Loudspeakers”, Nano Letters, Vol. 8, No. 12, p 4539-4545 (2008)). The loudspeaker includes a carbon nanotube film acting as a thermoacoustic element. The carbon nanotube film is flexible, and easily shaped. Metal has good plasticity properties and can be formed into various shapes. The methods for manufacturing metal are mature. Thus, the metal generally can form a metal supporter to support a flexible film. However, the carbon nanotube film and metal both have electrically conductive properties, if the carbon nanotube film is located on the metal supporter, it will be easy short circuit. Thus, the loudspeaker cannot generate sound. Therefore, the thermoacoustic device is not suitable for employing a metal supporter.
A thermoacoustic device employing a metal supporter is provided.